{

enum class SchemaFormat

{

JSON = 0,

};

static constexpr size_t MAX_TYPED_PATHS = 1000;

static constexpr size_t MAX_DYNAMIC_PATHS_LIMIT = 10000;

/// Don't change this constant, it can break backward compatibility.

static constexpr size_t DEFAULT_MAX_DYNAMIC_PATHS = 1024;

static constexpr const char * SPECIAL_SUBCOLUMN_NAME_FOR_DISTINCT_PATHS_CALCULATION = "__special_subcolumn_name_for_distinct_paths_calculation";

/// Prefix character for sub-object subcolumns, e.g. "^`some`.path.path".

static constexpr char SUB_OBJECT_SUBCOLUMN_PREFIX = '^';

/// Prefix character for combined literal+sub-object subcolumns, e.g. "@`some`.path.path".

static constexpr char COMBINED_SUBCOLUMN_PREFIX = '@';

explicit DataTypeObject(

const SchemaFormat & schema_format_,

std::unordered_map<String, DataTypePtr> typed_paths_ = {},

std::unordered_set<String> paths_to_skip_ = {},

std::vector<String> path_regexps_to_skip_ = {},

size_t max_dynamic_paths_ = DEFAULT_MAX_DYNAMIC_PATHS,

size_t max_dynamic_types_ = DataTypeDynamic::DEFAULT_MAX_DYNAMIC_TYPES);

DataTypeObject(const SchemaFormat & schema_format_, size_t max_dynamic_paths_, size_t max_dynamic_types_);

const char * getFamilyName() const override { return "Object"; }

String doGetName() const override;

TypeIndex getTypeId() const override { return TypeIndex::Object; }

MutableColumnPtr createColumn() const override;

Field getDefault() const override { return Object(); }

void insertDefaultInto(IColumn & column) const override;

bool isParametric() const override { return true; }

bool canBeInsideNullable() const override { return true; }

bool supportsSparseSerialization() const override { return false; }

bool canBeInsideSparseColumns() const override { return false; }

bool isComparable() const override { return true; }

bool isComparableForEquality() const override { return true; }

bool haveSubtypes() const override { return false; }

bool equals(const IDataType & rhs) const override;

void updateHashImpl(SipHash & hash) const override;

void forEachChild(const ChildCallback &) const override;

bool hasDynamicSubcolumnsData() const override { return true; }

bool hasDynamicStructure() const override { return true; }

std::unique_ptr<SubstreamData> getDynamicSubcolumnData(std::string_view subcolumn_name, const SubstreamData & data, size_t initial_array_level, bool throw_if_null) const override;

SerializationPtr doGetSerialization(const SerializationInfoSettings & settings) const override;

const SchemaFormat & getSchemaFormat() const { return schema_format; }

String getSchemaFormatString() const;

const std::unordered_map<String, DataTypePtr> & getTypedPaths() const { return typed_paths; }

const std::unordered_set<String> & getPathsToSkip() const { return paths_to_skip; }

const std::vector<String> & getPathRegexpsToSkip() const { return path_regexps_to_skip; }

size_t getMaxDynamicTypes() const { return max_dynamic_types; }

size_t getMaxDynamicPaths() const { return max_dynamic_paths; }

DataTypePtr getTypeOfNestedObjects() const;

DataTypePtr getDynamicType() const;

/// Shared data has type Array(Tuple(String, String)).

static const DataTypePtr & getTypeOfSharedData();

/// Don't change these constants, it can break backward compatibility.

static constexpr size_t NESTED_OBJECT_MAX_DYNAMIC_PATHS_REDUCE_FACTOR = 4;

static constexpr size_t NESTED_OBJECT_MAX_DYNAMIC_TYPES_REDUCE_FACTOR = 2;

SchemaFormat schema_format;

/// Set of paths with types that were specified in type declaration.

std::unordered_map<String, DataTypePtr> typed_paths;

/// Set of paths that should be skipped during data parsing.

std::unordered_set<String> paths_to_skip;

/// List of regular expressions that should be used to skip paths during data parsing.

std::vector<String> path_regexps_to_skip;

/// Limit on the number of paths that can be stored as subcolumn.

size_t max_dynamic_paths;

/// Limit of dynamic types that should be used for Dynamic columns.

size_t max_dynamic_types;